Method and apparatus for dual lever wheelbarrow

ABSTRACT

A wheelbarrow including a first lever providing at least one handle rigidly coupled to a second lever providing a bucket for carrying a payload. A lever assembly including the first lever rigidly coupled to the second lever. Kits including the levers or the lever assembly. Manufacturing processes for the wheelbarrow and the lever assembly including converting a conventional wheelbarrow.

CROSS REFERENCE TO RELATED PATENT APPLICATIONS

This application claims priority to provisional application Ser. No. 60,678,706, filed May 9, 2005 and entitled “Levered load wheel barrow”.

TECHNICAL FIELD

This invention relates to wheelbarrows, in particular, to wheelbarrows having handles provided by a first lever rigidly coupled to a second lever supporting a payload.

BACKGROUND OF THE INVENTION

Contemporary wheelbarrows typically include a first lever providing at least one handle and a bucket, mounted upon at least one wheel. They are possibly the oldest wheeled machine in the world and haven't changed much in quite a long time.

The inventor found a problem where others saw a situation, namely, the lifting ratio for the wheelbarrow was inherently limited because the handles need to be close to the rest of the unit to maintain the maneuverability. He realized there was a way to achieve the equivalent of a long lever arm for a wheelbarrow, while maintaining its compact and maneuverable qualities.

SUMMARY OF THE INVENTION

The invention's wheelbarrow includes a first lever providing at least one handle and rigidly coupled to a second lever providing a bucket for carrying a payload. The use of two rigidly coupled levers provides an improved lifting ratio between the force applied at the handle to lift a payload weight in the bucket when compared with traditional single lever wheelbarrows. This improved lifting ratio cannot be achieved with traditional, single lever wheelbarrows without making the handles prohibitively long, rendering them too awkward for normal use.

The first lever may further provide a second handle.

Certain preferred embodiments of the wheelbarrow use a lever assembly including the first lever for providing at least one handle and rigidly coupled to the second lever for providing a bucket for a payload. When constructed this way, the wheelbarrow includes the lever assembly providing the at least one handle and the bucket and the lever assembly mounted on at least one wheel. The first lever further provides the at least one handle, and the second lever further provides the bucket.

The lever assembly may further be mounted on at least two wheels.

The wheel or wheels may be mounted to at least one of the first lever, the second lever and/or a joint coupled between the first lever and the second lever.

Manufacturing the wheelbarrow may include coupling the lever assembly to the bucket to create the second lever providing the bucket, and mounting the lever assembly to the at least one wheel to create the lever assembly mounted to the wheel. Manufacturing the wheelbarrow may includes coupling the first lever to the second lever to create the lever assembly, coupling the bucket to the second lever, and mounting the at least one wheel to the lever assembly to create the wheelbarrow.

The invention includes a wheelbarrow kit for making the wheelbarrow, including the at least one wheel, the bucket, the first lever and the second lever.

The invention includes the wheelbarrow as a product of any of these manufacturing processes.

The invention includes a lever assembly kit including the first lever and the second lever, and manufacturing the lever assembly by rigidly coupling the first lever to the second lever to create the lever assembly.

Alternatively, manufacturing the lever assembly may include forming the first lever rigidly coupled to the second lever to create the lever assembly. The step of forming may further include forming the first lever rigidly coupled to the second lever providing the bucket to create the lever assembly.

The invention includes the lever assembly as a product of any of these manufacturing processes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a prior art wheelbarrow;

FIGS. 1B to 4B show various embodiments and details of the invention's wheelbarrow;

FIG. 4C shows a prior art wheelbarrow in the experimental setup described herein;

FIG. 4D shows an embodiment of the invention's wheelbarrow in the experimental setup;

FIG. 5A shows a preferred embodiment of the invention's wheelbarrow positioning the wheel below the center of gravity of the bucket when uniformly filled with a payload; and

FIG. 5B shows a prior art wheelbarrow used to create the invention's wheelbarrow through the introduction of a wedge as shown in FIG. 5C.

DETAILED DESCRIPTION

This invention relates to wheelbarrows, in particular, to wheelbarrows having handles provided by a first lever rigidly coupled to a second lever supporting a payload.

The invention's wheelbarrow Wnew includes a first lever L1 providing at least one handle H and rigidly coupled to a second lever L2 providing a bucket B for carrying a payload, as shown in FIGS. 1B to 4B, 4D, 5A and 5C.

The use of the two rigidly coupled levers provides an improved lifting ratio between the force applied at the handle to lift a payload weight in the bucket when compared with traditional single lever wheelbarrows. This improved lifting ratio cannot be achieved with traditional, single lever wheelbarrows without making the handles prohibitively long, rendering them too awkward for normal use. In an experiment performed by the inventor, two wheelbarrows with similar first lever L1, wheel W, rest R, and bucket B, were each placed on a block to measure their handle force for the same payload weight PW. FIG. 4C shows the experimental setup for the prior art wheelbarrow with a prior art handle force HFO and FIG. 4D shows the setup for the invention's wheelbarrow Wnew with a handle force HF. The scale in each case was adjusted to compensate for the empty weight of the wheelbarrow. The prior art wheelbarrow showed the prior art handle force essentially the same as the payload weight. The handle force of the invention's wheelbarrow showed one third the payload weight, showing an improvement in the lifting ratio of a factor of three. The only way the traditional wheelbarrow could achieve this improvement is by having a handle length B three times longer the payload placement length A, whereas this can be achieved through the angular relationship between the first lever and the second lever as shown in FIG. 2C.

The first lever L1 may further provide a second handle H2, as shown in FIG. 3B.

Certain preferred embodiments of the wheelbarrow Wnew use a lever assembly LA including the first lever L1 for providing at least one handle H and rigidly coupled to the second lever L2 for providing a bucket B for a payload. When constructed this way, the wheelbarrow includes the lever assembly to provide the at least one handle and the bucket and the lever assembly mounted on at least one wheel W. The first lever further provides the at least one handle, and the second lever further provides the bucket.

The invention's wheelbarrow Wnew may further be preferred to mount the wheel W essentially over the center of gravity CG of the bucket B when filled with a uniform payload, as shown in FIG. 5A.

The lever assembly LA may further be mounted on at least two wheels, W and W2 as shown in FIGS. 4A and 4B.

The wheel W may be mounted to the first lever L1, the second lever L2 and/or a joint J coupled between the first lever and the second lever. By way of example, FIGS. 1B, 1C, 3B and 5A show the wheel mounted via a wheel mount WM to the first lever. FIG. 2B shows the wheel mounted via the wheel mount to the second lever. FIGS. 1D, 2A, 2C, 3A, and 4D shows the wheel mounted at the joint.

Manufacturing the wheelbarrow Wnew may include coupling the lever assembly LA to the bucket to create the second lever L2 providing the bucket B, and mounting the lever assembly to the wheel W to create the lever assembly mounted to the wheel. Manufacturing the wheelbarrow may further include coupling the first lever to the second lever to create the lever assembly, coupling the bucket to the second lever, and mounting the at least one wheel to the lever assembly to create the wheelbarrow.

The invention includes a wheelbarrow kit for making the wheelbarrow Wnew, including at least one wheel W, the bucket B, the first lever L1 and the second lever L2.

The invention includes the wheelbarrow Wnew as a product of any of these manufacturing processes.

The invention includes a lever assembly kit including the first lever L1 and the second lever L2, and manufacturing the lever assembly LA by rigidly coupled the first lever to the second lever to create the lever assembly.

Alternatively, manufacturing the lever assembly LA may include forming the first lever L1 rigidly coupled to the second lever L2 to create the lever assembly. The step of forming may further include forming the first lever rigidly coupled to the second lever providing the bucket B to create the lever assembly.

The invention includes the lever assembly as a product of any of these manufacturing processes.

The bucket B may vary in shape, size of walls, number of walls and materials the bucket is made from. The wheelbarrow may be made from wood, metal, and/or plastics, which may include rubber compounds.

The preceding embodiments provide examples of the invention and are not meant to constrain the scope of the following claims. 

1. A lever assembly for use in a wheelbarrow, comprising: a first lever for providing at least one handle and rigidly coupled to a second lever for providing a bucket for a payload.
 2. The wheelbarrow of claim 1, comprising: said lever assembly providing said at least one handle and said bucket, further comprising: said first lever providing at least one handle; and said second lever providing said bucket; and said lever assembly mounted on at least one wheel.
 3. The wheelbarrow of claim 2, wherein said first lever provides a second of said handles.
 4. The wheelbarrow of claim 2, wherein said lever assembly is mounted on at least two wheels.
 5. The wheelbarrow of claim 2, wherein said at least one wheel is mounted to at least one member of the group consisting of: said first lever; said second lever; and a joint coupled between said first lever and said second lever.
 6. The wheelbarrow of claim 5, wherein said at least one wheel is mounted via a wheel mount coupling to at least one of said member of said group.
 7. A method for manufacturing said wheelbarrow of claim 2, comprising the steps: coupling said lever assembly to said bucket to create said second lever providing said bucket; mounting said lever assembly to said at least one wheel to create said lever assembly mounted on said at least one wheel.
 8. The wheelbarrow as a product of the process of claim
 7. 9. A manufactured article directing an entity to perform the steps of claim 7 to create a wheelbarrow; wherein said manufactured article includes at least one member of the group consisting of: a robotic program system for directing a robot; a motion frame sequence portraying a human performing these steps; an audio sequence directing said human in performing these steps; and a text describing these steps.
 10. A wheelbarrow kit for making said wheelbarrow of claim 2, comprising: said at least one wheel; said bucket; said first lever; and said second lever.
 11. A method of manufacturing said wheelbarrow from said wheelbarrow kit of claim 10, comprising the steps: coupling said first lever to said second lever to create said lever assembly; coupling said bucket to said second lever; mounting said at least wheel to said lever assembly to create said wheelbarrow.
 12. The wheelbarrow as a product of the process of claim
 11. 13. A method of converting a conventional wheelbarrow with a first lever and a bucket into said wheelbarrow of claim 2, comprising the steps: coupling a wedge between said first lever and said bucket to create said second lever as the coupling surface of said wedge to said bucket to create said wheelbarrow; and wherein said second lever is non-parallel to said first lever.
 14. The wheelbarrow as a product of the process of claim
 13. 15. A lever assembly kit for making said lever assembly of claim 1, comprising: said first lever and said second lever.
 16. A method of manufacturing said lever assembly from said lever assembly kit of claim 15, comprising the steps: rigidly coupling said first lever to said second lever to create said lever assembly.
 17. The lever assembly as a product of the process of claim
 16. 18. A method for manufacturing said lever assembly of claim 1, comprising the step: forming said first lever rigidly coupled to said second lever to create said lever assembly.
 19. The method of manufacturing said lever assembly of claim 18, further comprising the step: forming said first lever rigidly coupled to said second lever providing said bucket to create said lever assembly.
 20. The lever assembly as a product of the process of claim
 18. 